If you want a primer on Wilkinson and Pickett's joint book The Spirit Level, then the pieces here are worth a look (one by me). And for a comprehensive set of responses to their critics, including a pre-emptive strike against Gerry Hassan’s recent piece on OK this is all you need. (It is worth noting too that Wilkinson and Pickett’s work is peer-reviewed; that of their critics isn’t.)

For me as a philosopher, the thing about The Spirit Level that is most exciting is that as a study of the pervasive harms of inequality it strongly suggests that John Rawls's 'difference principle', which says that inequalities are OK provided that they materially benefit the worst off, a principle that has dominated political philosophy for 40 years, is simply wrong. Empirically wrong.

How ought we to think of our relationship to — our responsibility for — future people? Is this question (a question pressing all the harder in the wake of the recent failure to adequately safeguard those future people, at Copenhagen) essentially a question of justice? The rallying cry at Copenhagen was, "What we do we want? Climate justice! When do we want it? Now!" But what if it's not enough to call for justice?

Many voters are 'against immigration' and against foreign aid (they say things to me on the doorstep along the lines of: "We should take care of our own; that's enough"); and yet they insist that they are not racists. This includes many Tories and the whole of UKIP – and many ordinary voters.

My reaction, perhaps like yours, is to suspect that, actually, in many cases they are racists. But it is hard to prove that; dangerous to say it (at least, to someone's face) – and, I increasingly suspect, not always true, not by any means.

It is no longer socially-acceptable to exhibit prejudice against ethnic minority people on grounds of their ethnicity, women on grounds of their gender, or working-class people on grounds of their class. The last bastions of discrimination are being overcome: such as prejudice against gay and lesbian people, and against disabled people.

But is there one crucial bastion of discrimination still strongly in place?

If something bad happens, people who had warned that it was likely often say, "I don't like to say it, but, I told you so!"

Why is it that one is supposed not to like to say it?

Is it perhaps that we don't like to admit it when we were wrong, especially when we were warned that we were wrong? Are people who make us realise that we made a predictable - almost wilful - mistake unwelcomed because of that fact?

The honest truth is that we ought to listen to those who told us so. They saw it coming – they will be better at heading it off, next time.

Some people think the rhetoric of climate change is too emotive. But faced with a global catastrophe it would be unwise to tone down our language.

We are all familiar by now with the shrill voices of climate change deniers. But with every passing week they become more and more irrelevant, as their 'scepticism' about the reality of man-made climate change is exposed as risible. The issue now is not whether we are certain that dangerous climate change is real and is happening - the issue is only how we are going to tackle it. So how do we motivate people to act? How do we persuade them not to seek refuge in psychological defence mechanisms of the kind Leo Hickman chronicled in the Guardian last week?